Modeling the Input Optics with e2e

T. Findley, S. Yoshida, D. Dubois, N. Jamal, and R. Dodda

Southeastern Louisiana University

LIGO-G050219-00-D

Objectives

Report status of e2e modeling Results

Calibrated floor motion Better Mode Cleaner Mode Matching Telescope in Detector.box

Comments/Suggestions

Contents Estimate the table top motion for a given ground

motion. Make a Small Optic Suspension (SOS) box with

local damping, and find optimal gain settings to damp the optic when estimated table top motion is given.

Create a Mode Cleaner (MC) box, and implement the length control for the mode cleaner cavity.

Put all the optics (MCs, SM, and MMTs) in order, and create the Input Optic (IO) box.

Use the IO box in Simligo, and run the simulation for the entire detector.

Input Optics

Table Motion

HAM table

Vibration

isolation

stacks

Accelerometer

Suspension Point

Tower

Wire

OSEM Sensors

dtdtACCXtx )(

HAM box

Calibrating the Table Motion

MC1 box

ITMX pend/yaw with balanced OSEMs

Pendular Yaw

OSEM sensor imbalance

UL

LL

UR

LR

UR= (P + Y + T) g1

UL= (P - Y + T) g2

LL= (P - Y - T) g3

LR= (P + Y - T) g4

OSEM P = UR+UL+LL+LR = (P+Y+T)g1 + (P-Y+T) g2 + (P-Y-T) g3 + (P +Y-T) g4

=(g1+g2+g3+g4)P + (g1-g2-g3+g4)Y + (g1+g2-g3-g4)T

OSEM Y = UR–UL–LL+LR = 0.1P+3.9Y+0.1T

= 0, if g1=g2=g3=g4 If g1=1.05, g2=g3=g4=0.95

ITMX pend/yaw with pend/yaw ratio = 0.023

Pendular Yaw

Mode Cleaner

Mode Cleaner Continued

MC Transmission and MC2 motion

MC Transmitted Power

DAQE2E

Frequency Domain

Time Domain

MC Beam Motion

Beam center 20 meters away from MC pitch (lower)

Time Domain

Frequency Domain

yaw

pitc

h

Detector box

Status of IO box: Contains MMT optics only

MMT1 motion effect on CARM and DARM error signals

Time (sec)

Time (sec)

Dis

pla

cem

ent

(m o

r ra

d)

MMT3 motion effect on CARM and DARM

Time (sec)

Dis

pla

cem

ent

(m o

r ra

d)

Time (sec)

Power Behind ETMx due to MMT1 and MMT3 motion

Power Behind ETMx due to MMT optics motion

Summary

Produced a better representation of the table translational and yaw motion

Created a Mode Cleaner box with Length Sensing Control

Put the Mode Matching Telescope into Detector box

Will continue investigating the effect of table motion on the optic and the resultant beam motion

Will include Mode Cleaner box in Detector box

Acknowledgements

People: B. Bhawal M. Evans H. Yamamoto

Organizations LIGO Livingston Observatory National Science Foundation Southeastern Louisiana University